From the Start menu open the \Programs\Norton AntiVirus path and select the "Uninstall Norton AntiVirus" entry.
Click the "Yes" button to confirm and the program will be removed.

OR,

Open the "Control Panels" folder from the "Settings" slot on the Start Menu.
Double-click on the "Add/Remove Programs" icon.
Scroll down the list until you find the "Norton AntiVirus 5.0 for Windows" entry, then click on the "Add/Remove..." button and click yes to confirm. The program will now be uninstalled.